/*
Copyright IBM Corp. 2016 All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

		 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// The 'viper' package for configuration handling is very flexible, but has
// been found to have extremely poor performance when configuration values are
// accessed repeatedly. The function CacheConfiguration() defined here caches
// all configuration values that are accessed frequently.  These parameters
// are now presented as function calls that access local configuration
// variables.  This seems to be the most robust way to represent these
// parameters in the face of the numerous ways that configuration files are
// loaded and used (e.g, normal usage vs. test cases).

// The CacheConfiguration() function is allowed to be called globally to
// ensure that the correct values are always cached; See for example how
// certain parameters are forced in 'ChaincodeDevMode' in main.go.

package peer

import (
	"fmt"
	"io/ioutil"
	"net"

	"github.com/spf13/viper"

	"github.com/hyperledger/fabric/core/comm"
	"github.com/hyperledger/fabric/core/config"
	pb "github.com/hyperledger/fabric/protos/peer"
)

// Is the configuration cached?
var configurationCached = false

// Cached values and error values of the computed constants getLocalAddress(),
// getValidatorStreamAddress(), and getPeerEndpoint()
var localAddress string
var localAddressError error
var peerEndpoint *pb.PeerEndpoint
var peerEndpointError error

// Cached values of commonly used configuration constants.

// CacheConfiguration computes and caches commonly-used constants and
// computed constants as package variables. Routines which were previously
// global have been embedded here to preserve the original abstraction.
func CacheConfiguration() (err error) {

	// getLocalAddress returns the address:port the local peer is operating on.  Affected by env:peer.addressAutoDetect
	getLocalAddress := func() (peerAddress string, err error) {
		if viper.GetBool("peer.addressAutoDetect") {
			// Need to get the port from the peer.address setting, and append to the determined host IP
			_, port, err := net.SplitHostPort(viper.GetString("peer.address"))
			if err != nil {
				err = fmt.Errorf("Error auto detecting Peer's address: %s", err)
				return "", err
			}
			peerAddress = net.JoinHostPort(GetLocalIP(), port)
			peerLogger.Infof("Auto detected peer address: %s", peerAddress)
		} else {
			peerAddress = viper.GetString("peer.address")
		}
		return
	}

	// getPeerEndpoint returns the PeerEndpoint for this Peer instance.  Affected by env:peer.addressAutoDetect
	getPeerEndpoint := func() (*pb.PeerEndpoint, error) {
		var peerAddress string
		peerAddress, err := getLocalAddress()
		if err != nil {
			return nil, err
		}
		return &pb.PeerEndpoint{Id: &pb.PeerID{Name: viper.GetString("peer.id")}, Address: peerAddress}, nil
	}

	localAddress, localAddressError = getLocalAddress()
	peerEndpoint, _ = getPeerEndpoint()

	configurationCached = true

	if localAddressError != nil {
		return localAddressError
	}
	return
}

// cacheConfiguration logs an error if error checks have failed.
func cacheConfiguration() {
	if err := CacheConfiguration(); err != nil {
		peerLogger.Errorf("Execution continues after CacheConfiguration() failure : %s", err)
	}
}

//Functional forms

// GetLocalAddress returns the peer.address property
func GetLocalAddress() (string, error) {
	if !configurationCached {
		cacheConfiguration()
	}
	return localAddress, localAddressError
}

// GetPeerEndpoint returns peerEndpoint from cached configuration
func GetPeerEndpoint() (*pb.PeerEndpoint, error) {
	if !configurationCached {
		cacheConfiguration()
	}
	return peerEndpoint, peerEndpointError
}

// GetSecureConfig returns the secure server configuration for the peer
func GetSecureConfig() (comm.SecureServerConfig, error) {
	secureConfig := comm.SecureServerConfig{
		UseTLS: viper.GetBool("peer.tls.enabled"),
	}
	if secureConfig.UseTLS {
		// get the certs from the file system
		serverKey, err := ioutil.ReadFile(config.GetPath("peer.tls.key.file"))
		serverCert, err := ioutil.ReadFile(config.GetPath("peer.tls.cert.file"))
		// must have both key and cert file
		if err != nil {
			return secureConfig, fmt.Errorf("Error loading TLS key and/or certificate (%s)", err)
		}
		secureConfig.ServerCertificate = serverCert
		secureConfig.ServerKey = serverKey
		// check for root cert
		if config.GetPath("peer.tls.rootcert.file") != "" {
			rootCert, err := ioutil.ReadFile(config.GetPath("peer.tls.rootcert.file"))
			if err != nil {
				return secureConfig, fmt.Errorf("Error loading TLS root certificate (%s)", err)
			}
			secureConfig.ServerRootCAs = [][]byte{rootCert}
		}
		return secureConfig, nil
	}
	return secureConfig, nil
}